The present invention relates to a display control device of an audio/visual system equipped with at least a small-sized display for audio-system, and a control method. More particularly, the invention relates to a display control device and method, which enables the display of navigation information (route guidance information) by utilizing the small-sized display provided for audio-system.
In vehicle-mounted audio/visual and navigation systems of, for example, automobiles, it has been common practice to provide a large-sized liquid crystal display 61 of approximately 5 inches as a means of displaying navigational information as shown in FIG. 6. More specifically, audio/visual equipment 62 having a small-sized liquid crystal display 621 for displaying audio or visual operating conditions in the form of characters, and navigation equipment 63 are connected via respective signal lines 64, 65 to the large-sized liquid crystal display 61 and when navigation display is selected by pushing a selection button provided to the large-sized liquid crystal display 61, the present position of one's own car and surrounding map information are displayed on the large-sized liquid crystal display 61 according to positional information obtainable from the GPS receiver of the navigation equipment 63 and the map data read from CD-ROM.
Alternatively, when visual display is selected, the TV broadcasting received by the audio/visual equipment 62 or the video image reproduced by the audio/visual equipment 62 is displayed on the large-sized liquid crystal display 61.
FIG. 7 is a schematic diagram illustrating a conventional audio/visual system configuration in that a large-sized liquid crystal display is not provided or, even if a large-sized LCD is provided but it is retracted in the case body. In such cases, the operating condition of navigation equipment may be displayed on the display of audio/visual equipment.
In FIG. 7, a signal line 66 is used to connect audio/visual equipment 62 and navigation equipment 63 and when the navigation equipment 63 is in operation, a character such as "NAVIGATION" is displayed on the small-sized liquid crystal display 621 of the audio/visual equipment 62.
However, there is a problem with the system of displaying navigational information (route guidance information) on the large-sized liquid crystal display as aforesaid in that the navigational function is not fully demonstrated because a detailed map picture and the like cannot be displayed unless the large-sized liquid crystal display is installed.
In the system of utilizing the small-sized liquid crystal display of the audio/visual equipment, moreover, it can only be displayed whether or not the navigation equipment is in operation and therefore route guidance can be given only in voice.